Ordinary chondrite

meteorite

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The Ankober meteorite, a stony meteorite classified as an ordinary chondrite, which fell in Ethiopia in 1942. One surface has been sawed and polished, revealing the internal structure. The light spots are nickel-iron alloy; the surrounding gray matrix is composed of silicate minerals. (Top left) J.A. Wood; (others) Smithsonian Institution

A thin section of the Tieschitz meteorite, an ordinary chondrite that fell in 1878 in an area currently in the Czech Republic, shown in a microscopic view. The rounded light-coloured objects are chondrules, some of which have been fractured by collisions after their formation.J.A. Wood

…the same minerals found in ordinary chondrites, but they also are present in a number of other meteorite types. The C class asteroids (e.g., Mathilde, observed by NEAR Shoemaker) have low albedos, and their more featureless spectra indicate the presence of light-absorbing materials, although at least half have a spectral…

…radionuclide aluminum-26 in chondrules from ordinary and carbonaceous chondrites have been interpreted to indicate that they formed over an extended period from 1 million to at least 3 and perhaps as long as 10 million years after the refractory inclusions. There is some debate, however, over whether these ages, particularly…